Malleny glasshouses renewed in major conservation projects

‘As any gardener will know, the usefulness of a greenhouse is limited only by your imagination. Even a small greenhouse helps make a garden more productive, and the Trust’s heritage greenhouses do the same thing. They’re a bit older, a bit bigger, a bit harder to maintain, but essentially do the same thing. Without them, Malleny Garden would not be where it is. Many of our plants will pass through the greenhouses in some way, and they also provide our gardeners with a useful space to get out of the weather to work, or sit and enjoy the plants.’

James Bell, Head Gardener at Malleny Garden on the outskirts of Edinburgh, is an inspiring advocate for having a greenhouse. However, he also knows the challenges of conserving heritage glasshouses such as the ones at Malleny, especially when they’re part of an A-listed property, have architectural and historic importance, and have endured the Scottish climate for well over a century.

Over the course of 2023–24, the Trust has completed a complex project to repair, maintain, conserve and redecorate two historic glasshouses at Malleny, involving substantial and skilled work to repair their brick plinth walls, replace decayed timber and renew glazing. The project to conserve the glasshouses, which are vital working buildings as well as part of the visited garden, has been made possible by support from Historic Environment Scotland (HES) through its Partnership Fund Grant and earlier Organisational Support Fund, as well as generous support received from the National Trust for Scotland Foundation USA (NTSUSA).

The glasshouses at Malleny Garden are likely to date back to 1883–93, with both featuring in an 1893 Ordnance Survey map of Malleny. The Large Glasshouse is known to be designed by MacKenzie & Moncur, still has the M&M brass plaque above the door, and can be seen in its 1892 catalogue. The Small Greenhouse is also thought to be a MacKenzie & Moncur glasshouse, based on its style and similar designs in the catalogue.

Gardener James Bell continues: ‘Like most exterior wood, the wood in our greenhouses eventually needed repaired or replaced. While MacKenzie & Moncur will likely have offered some sort of guarantee on their work, it is unlikely they would have guaranteed the timber for 130 years of outdoor use!’

Given the extent of the work involved, the Trust split the project into two distinct phases, with work on the Large Glasshouse at Malleny taking place during the first half of 2023 and supported by the HES Organisational Support Fund, and work on the Small Glasshouse beginning in August 2023, thanks to the HES Partnership Fund and NTSUSA. Our charity engaged specialist surveyors Adams Napier Partnership to manage the works, which were undertaken by heritage contractors Crown Traditional Craftsmen.

Ashley Turner, the Trust’s Regional Buildings Surveyor, said: ‘We’re grateful to the team that delivered both projects, with a complex plan of work that included stripping out intrusive vegetation from the brick walling, raking out and repointing open joints, replacing decayed timber rafters, sills and glazing bars, replacing glazing, and finally redecorating. Care was taken to record the condition of each timber element and to faithfully replicate moulded profiles for replacement timber. All metal elements were carefully taken back to bare metal to be repaired and eventually reinstated in their original position and redecorated. Only where considered necessary and to improve the performance and longevity of the glasshouse were small adjustments made.

‘Among the historic features retained in the conservation project are the Small Glasshouse’s ventilation mechanism, whereby the entire roof apex can be lifted by pulling down a level inside the structure. We’re not aware of any other examples of this ventilation system in Scotland or elsewhere, potentially making it the only one of its kind.’